It’s that time of year again, when everyone does some kind of “year in review” post. I figured I might as well do one for non-mammalian synapsids, a subject which I find interesting that often gets overlooked in favor of dinosaurs.

One of the year’s most remarkable stem-mammal discoveries is the new varanopid Ascendonanus, from the early Permian of Germany. Ascendonanus is the earliest known arboreal animal and is known from numerous specimens with well-preserved soft tissue, showing that varanopids were scaly (Spindler et al. 2018). However, a restudy of the early diapsid Orovenator has led to the discovery that varanopids may be diapsids, not synapsids (Ford and Benson 2018).

The late Permian of Russia has two new predators. Nochnitsa is the most basal gorgonopsian known, and one of the smallest (Kammerer and Masyutin 2018a). The real apex predator of its ecosystem was the much larger Gorynychus, a therocephalian (Kammerer and Masyutin 2018b).

A specimen of the tritylodontid cynodont Kayentatherium was found alongside a clutch of 38 babies, showing that unlike mammals, non-mammaliaform cynodonts were still r-strategists that didn’t invest heavily in parental care (Hoffman and Rowe 2018).

At nearly ten tonnes, Lisowicia, a new dicynodont from the Late Triassic of Poland, is the largest known non-mammalian synapsid and is neck-and-neck with contemporary early sauropods such as Lessemsaurus for being the largest known Triassic land animal (Sulej and Niedźwiezki 2018).

Dicynodonts weren’t just equaling the size of sauropodomorphs, they were living alongside them. A new dicynodont, Pentasaurus, has been discovered in the Lower Elliot Formation, making it a contemporary of early sauropodomorphs such as Melanorosaurus, Blikanasaurus, and “Thotobolosaurus,” and one of the few Late Triassic dicynodonts (Kammerer 2018).

A new edaphosaurid, Gordodon, is the fifth confirmed genus of this group of sail-backed herbivores. It had an unusually long neck for an early synapsid and an almost rodent-like tooth arrangement of incisor-like front teeth and molar-like back teeth, unique among such early land animals (Lucas et al. 2018).

Other discoveries include a new burnetiamorph, Leucocephalus, a new traversodontid cynodont, Siriusgnathus, and another varanopid, Microvaranops.

Best of the year:

• Best Name: Gorynychus: A name with a double meaning, as an allusion to the dragon of Russian folklore, Zmey Gorynych, and a combination of the English word “gory” with the Greek word “onychus,” meaning “claw.”
• Weirdest: Ascendonanus, narrowly beating out Gordodon.
• Awesomest: Lisowicia.